The present invention relates to Tonneau Covers, particularly Tonneau Covers including a flexible cover and an apparatus for attaching the flexible cover to a cargo box of a pickup truck; the apparatus includes a rear bar or end plate and end plate engagement members cooperating to impart tension to the flexible cover when the end plate pivots into or is positioned in a closed position with respect to the end plate engagement members; and, a locking member or members preventing unauthorized detachment of the end plate from the end plate engagement members.
Numerous protective covers for preventing rain, debris and wind from damaging or disrupting the contents of a pickup truck bed are currently available. Generally, the covers are made of some sort of fabric, often coated with a polymeric material, which is detachably fastenable to a rigid frame so as to enclose and protect a given area. The covering materials used are generally stretchable to the extent that once they are in a position, they are pulled taut and then attached to the frame by numerous methods such as snaps, grommets, or hook and loop fasteners and stretcher bars.
The use of hook-and-loop type fasteners and stretcher bars to fasten a cover to a frame structure forms the subject matter of U.S. Pat. Nos. 5,076,338 (""338 patent) and 5,174,353 (""353 patent) issued to Steven Schmeichel et al., the disclosures of which are incorporated herein by reference.
In the Schieichel et al. patents, an edge portion of a covering fabric is attached to a generally L-shaped end plate or stretcher bar. The end plate is provided with a peak or crest, which pivotally contacts ends of the frame structure as the end plate is rotated into a fixed, stretching position. As the end plate rotates into the fixed, stretching position, an enlarged ridge of the end plate is either captured by a spring loaded lock element as depicted in a first embodiment, or engages and deflects a biased pawl element as depicted in a second embodiment. After the enlarged ridge passes the lock or pawl element, the lock or pawl element springs back to it""s undeflected state thereby maintaining the end plate in the fixed, stretching position. In order to move the end plate out of the fixed stretching position, the biasing force of the lock or the pawl element must be overcome. In the first embodiment, this biasing force may be overcome by the movement of the enlarged ridge as the end plate is pivoted out of the fixed stretching position. In the second embodiment, deflection of the pawl is best accomplished by manipulating a release member which projects from a portion of a latching member, or by opening the tailgate and manually disengaging the pawl from the enlarged ridge.
Although the Schmeichel et al. patents teach a number of significant improvements over the prior art, there are several limitations of the prior art, which are addressed and improved upon by the present invention.
One limitation of the first embodiment of the Schmeichel et al. patents, as depicted, is that the L-shaped lock member, by virtue of it""s resilient nature, merely imparts a dynamic force, which tends to maintain the end plate in the fixed stretching position. This force, however, can be overcome by the action of the enlarged ridge as it moves past the inclined portion of the L-shaped lock. Thus, the L-shaped lock does not function as a lock in a conventional sense.
A limitation of the second embodiment of the Schmeichel et al. patents is in the location and construction of the lock element. As depicted, the lock element comprises a pawl element, which is attached to one end of an elongated leaf spring. The other end of the leaf spring is attached to a connector, which in turn is connected to a side rail of the support frame structure. While this embodiment functions to lock the end plate and support frame structure in the fixed stretching position, it would appear that absent support, the pawl element may be forcibly disengaged and/or damaged by forcible movement of the end plate out of the fixed, stretching position.
Another limitation of the second embodiment of the Schmeichel et al. patents is that the end plate may be disengaged from the lock member by a person with knowledge of the location of the release member.
A limitation common to both the first and second embodiments of the Schmeichel et al. patents regards the attachment point and the design of the engagement member (or strike) which engages the end plate. As depicted in the drawings the strike is attached to the frame structure by a fastening element located a substantial distance from the inclined portion of the strike. This allows the strike to be flexed or bent upwardly in reaction to the stress forces exerted on the strike when the end plate is pivoted into and out of the fixed stretching position. Repeated flexure and/or bending may result in loosening and/or premature failure of the strike. Additionally, the strike includes a relatively thin lip portion which extends beyond the body of the strike and which rotatingly contacts the end plate as it is pivoted into and out of the fixed stretching position. This lip portion is subject to high amounts of stress and is subject to flexure and/or bending which may lead to premature failure.
Another limitation common to both the first and second embodiments of the Schmeichel et al. patents is in the attachment of the support frame about the perimeter of a cargo box of the vehicle. In Schmeichel et al., a support frame is attached to an inner sidewall by a C-shaped clamp. The effectiveness of the clamp may, however, become compromised by overtightening the clamping bolt and may lead to deformation and/or failure the body of the clamp. Additionally, due to the tapered vertical attachment portion of the frame support, there is a tendency for the clamp to become dislodged from the clamping position.
The present invention provides improvements which address these and other limitations associated with the prior art.
The present invention relates to a tonneau cover apparatus for attaching and locking a flexible cover about a cargo box of a vehicle such as a pickup truck. The apparatus preferably includes a support frame, which is removably attached about the perimeter of the cargo box of the vehicle. The flexible cover is preferably attached to the support frame at one end and to an end plate at the other end. The end plate is configured to pivotally engage an end plate engagement member, which is attached to the support frame. As the end plate pivots about the end plate engagement member, and preferably a second end plate engagement member on an opposing side of the support frame and the end plate translates into a fixed stretching position in which the flexible cover is stretched or tensed, so that a tension is placed on the cover. In preferred embodiments, the end plate is releasably retained in the fixed stretching position by a latching member which is attached to the support frame and/or by a locking member which is slidingly attached to the end plate and which may to be operatively connected to end plate. Preferably, the latching member is a flexible member which is biased toward a first position proximate the support frame in which the latching member resides, unless force is used to displace the latching member from the first position to a second position in which one end of the latching member is displaced away from the support frame. In preferred embodiments, the support frame includes an aperture through which an engagement portion of the latching member extends when the latching member is in the first position. In this position, the engagement portion prevents the end plate from disengaging from the fixed stretching position. Preferably, the latching member is made of a resilient, at least somewhat flexible polymeric material. Any relatively hard, flexible polymeric material, which will retain its shape when deformed, may be used, however, glass filled nylon is preferred. The latching member preferably has first and second ends and the first end is preferably attached to the support frame such that second end is biased up against a surface of the support frame to which the first end is secured. In preferred embodiments, the latching member is biased toward the first position in which the second end is biased against the surface of the support frame to which the first end is secured and the engagement portion of the latching member is extended through the aperture in the support frame such that it is in position to prevent the end plate from disengaging from the support frame and translating out of the fixed stretching position. In preferred embodiments, the latching member can be displaced from the first position when force is applied to the latching member proximate the second end, but the latching member, because of its resilient nature, will return to the first position when the application of force is terminated. Preferably, in this way, the latching member will reside in the first position, in which it will prevent the end plate from disengaging from the support frame, unless force is applied to the latching member which is sufficient to displace it from the first position.
An object of the present invention is to provide a resilient latch which is biased toward a position in which it effectively holds the flexible cover in a closed position in a manner in which the latch member is relatively easily displaced by the owner, when the owner wishes to have greater access to the cargo enclosed by the tonneau cover.
A further object is to do this in a convenient and efficient way offering a stronger latch and a better design which reduces the likelihood of failure when force is placed upon the latch by lifting the end plate when the latch is in the first position.
Another object of the present invention is to improve the attachment of the support frame to an inner sidewall of a vehicle.
Another object of the present invention is to reduce the risk of over tightening in an attachment clamp.
Another object of the present invention is to maximize and simplify securement of the end plate engagement member to the support frame.
Yet another object of the present invention is to reduce areas of high stress concentrations in the end plate engagement member.
Still another object of the present invention is to lessen the exposure of the latching member relative to the support frame.
Another object of the present invention is to minimize deflection of the engagement portion of the latching member in response to force exerted by the end plate.
Yet another object of the present invention is to provide a superior side bar securing clamp which withstands the normal stresses associated with securing the support frame to side walls of the pickup truck.
Still another object of the present invention is to reduce inadvertent and/or unauthorized disengagement of a flexible cover from a cargo box of a vehicle.